1. Field of the Invention
The present invention relates to a rotary tool for imparting rotation to a drill or the attachment element.
2. Description of the Prior Art
For securing a constructional part, which is formed, e.g., of a thin-wall metal piece, to a constructional component formed, e.g., of wood, a through-hole should be formed in the constructional part through which an attachment element can extend before it is secured in the constructional component. The through-hole in the constructional part can be formed, e.g., by the drilling head of a drill or of the attachment element, with the rotation being imparted to the drill or the attachment element by the rotary tool.
In order to be able to form a through-or receiving hole in the constructional part in a very short time with a small pressure applied to the rotary tool, in the past, the drill or the attachment element was driven with a very high rotational speed. The high rotational speed resulted in a sharp raise of the temperature in the working location which led to change in the mechanical properties of the material of the constructional component in this location, and drilling with the drill or the attachment element, in this location, was not any more possible. Instead, a very high friction was developed between the drilling head of the drill or the attachment element which resulted in burning of the drilling head and, thus, in the damage of the drill or the attachment element.
Accordingly, an object of the present invention is to provide a rotary tool for imparting rotation to a drill or an attachment element with which the damage of the drill or the attachment element, in particular, as a result of burning during the formation of a through-or receiving hole in a constructional part, will be prevented.